:root {
  color-scheme: dark light;
  --gap: 1rem;
  --border: 2px;
  --accent-color: deeppink;
}

html {
  box-sizing: border-box;  
  width: 100vw;
  height: 100vh;
  display: flex;   
  justify-content: center;
  outline-offset: calc(-1 * var(--gap));
}

*,
*:before,
*:after {
  box-sizing: inherit;
}

body {
  margin: var(--gap);
  font-family: system-ui, sans-serif;  
  width: calc(100% - 2 * var(--gap));
  height: calc(100% - 2 * var(--gap));  
  max-width: 80ch;
}

a {
  color: var(--accent-color);
}

button {
  outline-offset: calc(-1 * var(--gap));
}

img {
  height: auto;
  max-width: 100%;
}

img:not([src^="data:"]) {
  cursor: pointer;
}

main {
  border: solid 1px var(--accent-color);
  border-radius: var(--gap);
  padding: var(--gap);
  margin-block-end: var(--gap);
}

footer {
  margin-block-start: var(--gap);
  font-size: .75rem;  
}

.avatar {
  border-radius: 50%;
  width: 3rem;
  height: auto;
  vertical-align: middle;
}